Problem: Christopher walked his dog for $2$ kilometers on each of the past $10$ days. How many kilometers did Christopher walk his dog altogether?
Explanation: The total number of kilometers walked is the product of the number of kilometers walked each day and the number of days that Christopher went walking. The product is $2\text{ kilometers per day} \times 10\text{ days}$ $2\text{ kilometers per day} \times 10\text{ days}= 20\text{ kilometers}$ Christopher walked a total of $20$ kilometers.